Hearing Rehabilitation of Single-Sided Deafness: Benefit and Selection Criteria of Bone Anchored Hearing Aid and Contralateral Routing of Signal Hearing Aid
Korean Journal of Otorhinolaryngology-Head and Neck Surgery (대한이비인후과학회지 두경부외과학)
Korean Journal of Otorhinolaryngology-Head and Neck Surgery (대한이비인후과학회지 두경부외과학), Vol.56(6) : 339~345, 2013
Background and Objectives : There are two ways to route sound from a deaf hemifield to a functional ear: the bone anchored hearing aid (BAHA) and the contralateral routing of signal hearing aid (CROS HA). BAHA uses transcranial bone conduction; on the other hand, CROS HA uses air conduction. The objectives of this study were to evaluate the benefit of these auditory rehabilitation devices objectively and subjectively, and to analyze factors that affect daily using time.
Subjects and Method : We retrospectively reviewed the medical records of 19 patients who selected BAHA and 9 patients who selected CROS HA to undergo rehabilitation of unilateral hearing loss. Preoperative pure tone air and bone conduction thresholds, BAHA-aided thresholds and CROS HA-aided thresholds were measured. Hearing in noise test (HINT) was measured with unaided and aided in signal to noise ratio 10 (signal 75 dB HL, noise 65 dBA). Bern Benefit in Single-Sided Deafness Questionnaire (BBSS) was evaluated for all patients to assess subjective satisfaction and also, daily device using time was investigated.
Results : The aided pure tone audiometry was 44.58 dB HL, 42.71 dB HL for in BAHA and CROS HA, respectively, whereas the unaided PTA was 111.29, 103.28 dB HL for BAHA and CROS HA, respectively. The aided HINT was 63.03 and 64.06%, whereas the unaided HINT was 22.13% and 37.44% for BAHA and CROS, respectively. BBSS showed more satisfactory results with BAHA and CROS HA when compared unaided in all items. Daily using time did not correlate with the degree of satisfaction, better ear hearing levels or etiology.
Conclusion : It was found that not only the preoperative BAHA rod test and HA trials but also the customized and detail counseling were needed for single sided deaf patients to use auditory rehabilitation devices frequently.